Curcuma amada Roxb. (family Zingiberaceae), also commonly known as Mango Ginger, is cultivated and grows wild throughout India. The herb is rhizomatous with a leafy tuft, 60-90 cm high with white or pale yellow flowers in spikes in the centre of the tuft of leaves.
A number of chemicals have been identified as major components of Curcuma amada. Among these are ocimene, dihydro-ocimene, .alpha.-pinene, .alpha.-curcumene, .beta.-curcumene, linalool, cuminyl alcohol, keto-alcohol, camphor, turmerone, linalyl acetate, safrole, curcumin, myristic acid, car-3-ene, myrcene, 1,8-cineol, limonene, perillene, etc.
Hypersensitivity is defined as a state of altered reactivity in which the body reacts with an exaggerated immune response to a substance (antigen). Hypersensitivity may be caused by exogenous or endogenous antigens.
Hypersensitivity reactions underlie a large number of diseases. Amongst these allergic and autoimmune conditions are of great importance. A classification of hypersensitivity diseases is given by Parveen Kumar and Michael Clark in the textbook Clinical Medicine .sup.1
Type I hypersensitivity reactions (IgE mediated allergic reactions) are caused by allergens (specific exogenous antigens), e.g. pollen, house dust, animal dandruff, moulds, etc. Allergic diseases in which type I reactions play a significant role include asthma, eczema (atopic dermatitis), urticaria, allergic rhinitis and anaphylaxis.
Type II hypersensitivity reactions are caused by cell surface or tissue bound antibodies (IgG and IgM) and play a significant role in the pathogenesis of myasthenia gravis, Goodpasture's syndrome and Addisonian pernicious anaemia.
Type III hypersensitivity reactions (immune complex) are caused by autoantigens or exogenous antigens, such as certain bacteria, fungi and parasites. Diseases in which type III hypersensitivity reactions play a significant role include lupus erythematosus, rheumatoid arthritis and glomerulonephritis.
Type IV hypersensitivity reactions (delayed) are caused by cell or tissue bound antigens. This type of hypersensitivity plays a significant role in a number of conditions, e.g. graft-versus-host disease, leprosy, contact dermatitis and reactions due to insect bites.
A number of drug classes are available for the treatment of hypersensitivity reactions. Some of these are systemic and some are applied topically.
The corticosteroids are among the most widely used drugs for the treatment of hypersensitivity diseases. Corticosteroids primarily exert their pharmacological action by non-selectively inhibiting the function and proliferation of different classes of immune cells. Hereby hypersensitivity reactions are suppressed. Unfortunately the corticosteroids are associated with a number of serious side effects e.g. immuno-suppression, osteoporosis and skin atrophy (when applied topically).